Roller bearing assembles are known that include an explosion prevention gap between a rotating shaft and a housing, e.g., for electric motors. The explosion prevention provided by the explosion prevention gap enables the operation of such an electric motor in an environment, in which explosive gases could develop. The explosion prevention gap prevents such gases from igniting due to arcing or sparking near the rotating shaft.
In order to prevent the transmission of sparks through an explosion prevention gap that is large, on the one hand, and in order to prevent spark generation in the area of the explosion prevention gap caused by the walls of the explosion prevention gap rubbing together on the other hand, the structural components forming the explosion prevention gap must be manufactured with especially small tolerances. Furthermore, it has been shown that, when the width of the explosion prevention gap is corrected after the manufacture of the electric motor, deformations can occur during the transport or assembly of the electric motor, which deformations can lead to a rubbing and/or a grinding of the walls of the explosion prevention gap.
Further, it is known to form an explosion prevention gap in a winding shape in the form of a lamellar seal. In such a design, not only the tolerances in the radial direction, but also the tolerances in the axial direction, must be precisely controlled for the correct dimensioning of explosion prevention gaps.